In recent years, there have been numerous studies into the long-term harm that repetitive blows to the head have in athletes of all kinds. Markers in the form of tau staining that show neurofibrillary tangle deposits in the brain are considered signs of the injury-induced pathology associated with sports.

A certain amount of tau staining may not be abnormal, but the accumulation of tangles is not normal. The trauma-induced pathology can only be definitely diagnosed with autopsy and is called chronic traumatic encephalopathy (CTE).

A unique group of headbangers — not the heavy metal kind were recently studied to determine the overall consequences repetitive head blows had on their brains. The study, published this month in PLOS One, looked at woodpeckers. To be more precise, researchers studied 10 specimens from the Picadae family of birds that includes woodpeckers and sapsuckers.

As far back as 1976, woodpeckers had been looked at as a potential model to develop better neck and head protection for athletes. The birds have several evolutionary physical adaptions that may absorb the impact of the force generated with pecking.

Among them are sharp beaks that move independently and a tongue that can brace the skull. The skull has protective bone features, and the neck muscles absorb impact. It is theorized that the anatomical adaptions were an evolutionary process to mitigate trauma to the woodpecker brain.

The recent woodpecker study took advantage of the availability of 10 preserved woodpecker specimens. They were of variety of woodpecker species and had been collected from Michigan, Maine, Massachusetts, Canada and Mexico.

While all the birds can be considered to be headbangers and susceptible brain injury, only one bird the one from Michigan showed signs of the tau forming tangles that are considered the hallmark of brain pathology from sports injury.

Unlike humans, the woodpeckers do not avail themselves to other factors that may exacerbate a head injury. Research has shown that there are at least four elements that contribute to the symptoms of CTE in retired human athletes: the neurotrauma itself, chronic pain, substance use and career transition stress.

Mouse models of brain trauma have shown that performance-enhancing drugs in the form of androgenic-anabolic steroids will cause significantly greater axonal injury and neurologic pathology changes. This demonstrates that chronic exposure to performance-enhancing drugs can alter the immune response to traumatic brain injury.

While only one bird had distinct signs of brain injury, eight others showed evidence of the tau staining. The woodpeckers were compared to red-winged blackbirds none of which had tau staining.

It is not possible to conclude whether the tau accumulations were in any way harmful to the bird. The comparisons to human athletes are difficult as the brain, neck and skulls are so dissimilar. When considering the eons of years of evolution that produced the woodpecker's physical adaptions, it should be taken into consideration that the accumulations of tau might be an evolutionary adaptation that is protective to the brain.

Woodpeckers head bang into a tree at an incredibly high speed with a brain deceleration of 1,000 g with no injury. This compares to the 100 g impact considered to be concussive in football.

We certainly have a lot to learn from woodpeckers when it comes to head protection.